Pray or clean animals were taken on the Ark in larger numbers (seven pairs) to give them a jump-start.
Later, when the Law of Moses was given the clean and unclean animals were used as meat as well as sacrifice. It became necessary for dietary proposes for the list to be further refined.
Clear now?
A. Cricket
Can you translate this into English?
Also, why does god change His mind so often. Prior to the flood, people werre supposed to be vegetarians. After the flood, omnivores. After the Exodus, omnivors with restrictions. After Jesus, omnivores again. After Muhammed, restrictions again.